Minors: Energy Studies, Poverty Studies, Engineering Corporate Practice
Faculty Advisor: Jennifer Schaefer, Department of Chemical and Biomolecular Engineering
Research Area: Smart Distribution and Storage

Polymers in Next-Generation Rechargeable Batteries (Spring 2024)

Renewable energy is becoming increasingly important as society transitions away from using fossil fuels to power our lives. Batteries, specifically rechargeable batteries, are utilized in a variety of contexts, including electric vehicles, and may be used more in aircraft and transport of goods in the future. Important factors of rechargeable batteries include energy density, longevity, affordability, and safety. Lithium sulfur batteries with solid polymer electrolytes are potential future-generation devices for energy storage due to sulfur’s high energy density and affordability. Additionally, solid electrolytes have improved safety.

However, polysulfides, lithium sulfur battery reaction intermediates, move through the electrolyte which decreases the charge capacity of these lithium sulfur batteries. As the battery is discharged, these sulfur species are reduced through polysulfide intermediates (Li2Sx where x=2-8) to Li2S. Then, they are oxidized back to S8 upon the recharging of the battery. However, some of these polysulfide  intermediates can move through the electrolyte towards the anode. There, they can’t be oxidized back to S8 and can also block lithium movement. This decreases the discharge capacity of the battery. Blocking this polysulfide shuttle is critical to having longlasting lithium sulfur batteries. The goal of this work is to synthesize a polymer interlayer within the electrolyte to block polysulfide movement. This allows more sulfur utilization during battery discharge to maintain the energy dispensed during each cycle.

My role in this project is to synthesize a polymer interlayer in the electrolytes of lithium sulfur batteries to block the movement of polysulfides. I will synthesize the interlayer and analyze each interlayer through Nuclear Magnetic Resonance (NMR). Different procedures and compositions of monomers will be utilized to form the interlayer until a successful interlayer is formed. Once an interlayer is formed, I will test its ability to block polysulfide movement. To do this, I will place the interlayer between two films, one containing polysulfides and one without polysulfides. After the films are in contact, I will utilize sulfur analysis to test the sulfur content of each film and determine the effectiveness of the interlayer in blocking the polysulfide movement.

Final Report